Heat exchanger



HEAT EXCHANGER Giovanninossi, va della stazione 6s, Valle Lomellina, Italy Filed June 20,1951, Ser. No. 232,586 Claims priority, application Italy June 21, 1950 z claims. (ci. 122-235) .The present invention relates to heat exchangers. With known heat exchangers made up of spaced tubes,

nite @rates @fait there is a large area of contact provided by the outer surfaces |of the tubes,v but on the other hand there is very little turbulence in the uid so that the best possible heat exchange does-not takewplace. Bales are required for guiding the `fluid on the outside of the heat exchanging tubes in desired directions. Where finned heat exchanging elements are provided, any advantage to be derived from such elements is largely nulliied by the fact that such elements are extremely diflicult to clean because of the small spaces between the tins and as a consequence foreign bodies accumulate in the spaces between the fins and greatly detract from the heat transferring properties of such elements.

One of the objects of the present invention is to overcome the above drawbacks by providing a heat exchanger which includes the characteristic advantages of tubular heat exchanger elements and at the same time provides ber of bales for directing liuid in a desired direction.

A further object of the present invention is to provide a heat exhcanger which increases the rate of fluid ow in the direction of fluid flow so that as the temperature of the fluid decerases its rate of movement increases to compensate for a drop in the temperature of the iluid.

With the above object in view the present invention mainly consists of a heat exchanger appaartus which includes a plurality of spaced walls each of which is made up of a plurality of parallel tubes engaging each other along the lengths thereof and extending in a direction perpendicular to the `direction of a fluid owing between the spaced walls sa as to provide a turbulence in this iluid.

The spaced walls define for this fluid a passage which de-V creases in cross-section in the direction of fluid flow so that the rate of lluid ow increases in the direction of fluid llow to compensate for a drop in the temperature of the fluid.

The novel features which are considered as characteristie for the invention are set forth in particular in the appended claims. 'Ihe invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

Fig. 1 is in elevationalview of a preferred embodiment of the present invention, Fig. 1 showing the structure of Fig. `3 las seen from the lower side of Fig. 2 with the lower wall of Fig. 2 removed to show the arrangement of tubes behind this wall; and

Fig. 2 is a plan view of the apparatus down in Fig. 1

aI'I'OWS.

2,974,649 v. PatentedV Friar,V 1 4, 1961 2 Referring to the drawings, in which a preferred embodiment of the present invention is illustrated, it will be seen that the heat exchanger apparatus of the present invention comprises a plurality ,of spaced heat exchanging walls 14 which are adapted to guide a first fluid or the hot combustion gases produced inY a combustion chamber, not

shown in the drawings, along a predetermined path extending frorn the left end of the wall portions 14, as viewed in the drawings, to the opposite end of the Wall portions along the spaces therebetween as indicated by thewavy arrows in Figs. 1 and 2. VThe walls 14 are eachmade up of a plurality of parallel, vertically extending tubes which engage each other along the lengths thereof and which are'connected at the top and bottom ends to headers 15. The headers 15 have baies 17 located in the interior thereof so that thewater or other liquid in the tubes move in the direction of arrows Vshown inv Figs. 1 and 2. The heat exchanger walls 14 are respectively located along planes which converge towards each other in the direction of iluid ow so that the spaces between the wall portions 14 decrease in the direction of fluid ilow, whereby the speed o-f Vflow* ofthe hot combustion gases is increased as these gases flow along the wall portions 14 so that the gases are compelled to move with increasing speed through the decerasing spaces to compensate for the drop in temperature of the gases as they approach the right ends of thev wall portions as viewed in Figs. 1 and 2, that is, as the gases move towards the chimney not shown in the drawings. Since the wall portions 14 are formed from the plurality of parallel tubes which engage each other along the length thereof, the outer surfaces of these wall portions will be similar to liuted or Ycorrugated surfaces so as to promote turbulence in the gases owing through the spaces between the wall portions in a direction normal to the direction in which the tubes extend. This turbulence in the hot combustion gases flowing between the wall portions and the increasing speed with which these hot gases are forced to flow between the walls 14 increase in a highly novel manner the heat exchange between the first duid or the combustion gases flowing between the wall portions 14 and the second fluid located in the tubes from which the wall portions 14 are formed. i

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of heat exchangers differing lfrom the types described above.

While the invention has been illustrated and described as embodied in a heat exchanger having Walls formed of tubes which produce turbulence and which act as bafes, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any Way yfrom the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for van'- ous applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and Vrange of equivalence ofthe following claims.

What is claimed -as new and desired to be secured by Letters Patent is:

1. Heat exchanger apparatus comprising, in combination, a pair of spaced wall portions located opposite each other and adapted to guide a lirst fluid along a predetermined path extending from one end of said wall portions to an opposite end of said wall portions along the space therebetween, each of said wall portions comprising a plurality of tubes which engage each other along the 3 length thereof and extend in a direction normal to said predetermined path so as to present to said rst uid a corrugated surface whose corrugations are no1-mal to said path, whereby a. .turbulence is produced in -said first uid by said wall portionsto -enhance the heat transfer between said first uid and a second Huid in said tubes of said wall portions, said wall portions gradually approaching .each other from said one end thereof to said opposite end thereof along said predetermined path so that the space between said wall portions decreases, whereby the speed of flow of said rst uid is increased along said path to enhance the heat exchange with said second uid as the temperature of said rst uid decreases.

2. Heat exchanger apparatus comprising, in combina- 15 tion, a pair of'spaced wall portions located opposite each other and adapted to guide a rst iuid along a predetermined path extending from one end of said wall portions to an opposite end of said wall portions along the space therebetween, each of said wall portions comprsin-g a plurality of tubes which engage each other along the length thereof and extend in a direction normal to said predetermined path so as to present to said irst uid a corrugated surface whose corrugations are normal to said path, whereby a turbulence is produced by said rst Huid by said wall portions to enhance the heat transfer between said rst uid and a second nid in said tubes of said wall portions, said wall portions being located in nonparallel planes so that said wall portions gradually approach each other from said one end thereof to said opposite end thereof along said predetermined path so that the space between said wall portions decreases, whereby the speed of flow of said first fluid is increased along said path to enhance the heat exchange with said second fluid as the temperature of said rst fluid decreases.

References Cited in the Elle of this patent UNITED STATES PATENTS 639,952 Thornycroft Dec. 26, 1899 2,030,265 Nygaard Feb. 11, 1936 2,169,086 Auer Aug. 8, 1939 2,529,611 Kallam Nov. 14, 1950 FOREIGN PATENTS 47,562 Denmark July 10, 1933 941,258 France July 5, 1948 396,047 France Jan. 14, 1909 256,654 Switzerland Mar. 1, 1949 

